1. Field of the Invention
The present invention relates to a recording and playback apparatus and a recording method for use in a system for performing recording and playback operations using maximum likelihood decoding. The present invention also relates to an evaluation value calculating apparatus and method used in the recording and playback apparatus.
2. Description of the Related Art
In recording and playback apparatuses for optical recording media such as optical disks, recording conditions for performing a recording operation on the recording media, such as the pulse width and level of laser emission, are adjusted to their optimum values.
In general, the factors that determine the recording conditions include zero-cross points of playback signals and statistical mean and variance values of binarized timing edge errors. However, it is difficult for signal playback systems using maximum likelihood decoding to sufficiently increase the margin.